Fixed bug in field-is-zero detection
Fixed bug in truncate file (datafile was not properly initialized)


mysql-test/t/disabled.def:
  Enable ps_maria
storage/maria/ma_bitmap.c:
  Added reset of bitmap (for truncate)
storage/maria/ma_blockrec.c:
  Fixed bug in zero detection
storage/maria/ma_blockrec.h:
  New prototype
storage/maria/ma_create.c:
  Moved initialzation of datafile to separate function
storage/maria/ma_delete_all.c:
  Added initializtion of data file
storage/maria/maria_def.h:
  New prototype